Commit 578b016f authored by Kent Yoder's avatar Kent Yoder

hw_random: add support for the TPM chip as a hardware RNG source

This driver will make use of any available TPM chip on the system as a
hwrng source.
Acked-by: default avatarDavid Safford <safford@linux.vnet.ibm.com>
Signed-off-by: default avatarKent Yoder <key@linux.vnet.ibm.com>
parent 41ab999c
......@@ -289,3 +289,16 @@ config HW_RANDOM_EXYNOS
module will be called exynos-rng.
If unsure, say Y.
config HW_RANDOM_TPM
tristate "TPM HW Random Number Generator support"
depends on HW_RANDOM && TCG_TPM
default HW_RANDOM
---help---
This driver provides kernel-side support for the Random Number
Generator in the Trusted Platform Module
To compile this driver as a module, choose M here: the
module will be called tpm-rng.
If unsure, say Y.
......@@ -25,3 +25,4 @@ obj-$(CONFIG_HW_RANDOM_PICOXCELL) += picoxcell-rng.o
obj-$(CONFIG_HW_RANDOM_PPC4XX) += ppc4xx-rng.o
obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o
obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o
obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o
/*
* Copyright (C) 2012 Kent Yoder IBM Corporation
*
* HWRNG interfaces to pull RNG data from a TPM
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/hw_random.h>
#include <linux/tpm.h>
#define MODULE_NAME "tpm-rng"
static int tpm_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
{
return tpm_get_random(TPM_ANY_NUM, data, max);
}
static struct hwrng tpm_rng = {
.name = MODULE_NAME,
.read = tpm_rng_read,
};
static int __init rng_init(void)
{
return hwrng_register(&tpm_rng);
}
module_init(rng_init);
static void __exit rng_exit(void)
{
hwrng_unregister(&tpm_rng);
}
module_exit(rng_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Kent Yoder <key@linux.vnet.ibm.com>");
MODULE_DESCRIPTION("RNG driver for TPM devices");
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